If you live in the San Francisco Bay Area, you get used to the idea that "The Big One" is inevitable. Maybe you get too used to it. According to recent reports in The New York Times and the Los Angeles Times, San Francisco and nearby communities have been slow to address the risk to buildings there — and, in fact, are continuing to develop and build in risky locations without taking appropriate steps to limit the danger.
The New York Times published a long analysis of San Francisco development patterns on April 17
(see: "San Francisco’s Big Seismic Gamble," by Thomas Fuller, Anjali Singhvi, and Josh Williams).
"San Francisco lives with the certainty that the Big One will come," the Times reported. "But the city is also putting up taller and taller buildings clustered closer and closer together because of the state’s severe housing shortage. Now those competing pressures have prompted an anxious rethinking of building regulations. Experts are sending this message: The building code does not protect cities from earthquakes nearly as much as you might think."
What's the big gamble? Faced with a shortage of housing and a constrained footprint, the city has allowed dense high-rise development in an area of known high seismic hazard, the Times reported.
"How safe are San Francisco’s skyscrapers? Even the engineers who design them can’t provide exact answers," the paper reported. "Earthquakes are too unpredictable." And even the ground under many tall structures is unreliable, the Times noted: "At least 100 buildings taller than 240 feet were built in areas that have a 'very high' chance of liquefaction."
San Francisco's current prosperity, built on its status as a center of the high-tech revolution, would seem to put the city in a good position to finance upgrades. But the Los Angeles Times reports that the city is not seizing the opportunity (see: "Bay Area falling behind on quake safety despite booming tech economy," by Rong-Gong Lin II).
"The Bay Area was once the national leader in seismic safety," the Times reported. "Just five years ago, San Francisco made history by becoming the first of California’s largest cities to require property owners to retrofit wood-frame apartments at serious risk of collapse in a major quake, like the one that destroyed much of the city in 1906. Since then, however, new efforts have stalled in San Francisco and other surrounding cities, while communities in Southern California have expanded mandatory seismic retrofitting efforts. Some quake safety experts worry the Bay Area is missing a key opportunity to take advantage of the booming economy to make more fixes."